Technical Field
The present disclosure relates to a wrench and a warning method thereof. More particularly, the present disclosure relates to a wrench with multiple display windows and an optical warning method thereof.
Description of Related Art
A digital tool is a hand tool integrated with a digital detection and display mechanism for detecting a load of the hand tool by sensors, such as a wrench-like hand tool. A strain gauge is disposed in a wrench to measure a torque exerted on the wrench by using charge signals generated by the strain of the strain gauge. In addition, the display is also disposed on the wrench for showing the conditions of the wrench. It allows a user to control the torque and prevent accidents of excessive force from happening. However, it is difficult to observe the display of the wrench without any light or under a low light environment, or in a small space in which the wrench cannot be adjusted for fitting the user's viewing angle, so that the user cannot immediately understand the conditions of the wrench and cannot quickly know the increment of the torque by observing the display of the wrench. Hence, the probability of the accidents of excessive force is very high without any suitable warning mechanism.
A conventional wrench is configured to provide a sound warning to reduce the incidence of accidental excessive force. When the wrench is operated by the user, a torque is compared with a predetermined value to generate the sound warning by the wrench. If the torque is greater than or equal to the predetermined value, the wrench will be shut down and cannot be operated. However, the user usually overlooks the sound warning or does not hear the sound warning in a noisy environment. Therefore, the sound warning is not enough for the user to operate the wrench safely.
Another conventional wrench mainly includes a small hole and a LED light used to show the condition of the torque. If the torque is greater than or equal to the predetermined value, the LED light will be illuminated for reminding the user. However, such kind of small hole with the LED light is too small for user to observe clearly. In addition, the visual range of the small hole with the LED light is quite narrow, and the user cannot see the LED light within the visual range of the small hole. Further, another conventional wrench includes a small convex transparent surface and a LED light utilized to increase the visual range of the LED light. However, the wrench having the small convex transparent surface is easily broken or damaged due to motions of the wrench or being stamped by the user. Therefore, it is desirable to develop a wrench with quick warnings, a wide visual range, and being convenient to use.